Formula Relationship Between Wave Number and Angular Wave Number
$$k ~=~ 2\pi \, \nu$$ $$k ~=~ 2\pi \, \nu$$ $$\nu ~=~ \frac{k}{2\pi}$$
Angular wavenumber
$$ k $$ Unit $$ \frac{\mathrm{rad}}{\mathrm{m}} $$ Angular wave number indicates the covered phase angle of a wave per meter.
Wavenumber
$$ \nu $$ Unit $$ \frac{1}{\mathrm{m}} $$ Wavenumber indicates how many times the wavelength of a periodic wave fits into one meter.